Ultrahigh sensitive plasmonic terahertz detector based on an asymmetric dual-grating gate HEMT structure

We report on ultrahigh sensitive, broadband terahertz (THz) detectors based on asymmetric double-grating-gate (A-DGG) HEMTs demonstrating a record responsivity of 2.2 kV/W at 1 THz. Hydrodynamic nonlinearities of two-dimensional (2D) plasmons in high-electron-mobility transistors (HEMTs) are promising for fast and sensitive rectification/detection of THz radiation [1], which can be applied to real-time THz imaging/spectroscopic analysis and future THz wireless communications [2]. Recently, InP- and GaN-based HEMTs as well as Si-MOSFETs have demonstrated improved responsivities [3,4], approaching 1 kV/W at 1 THz by introducing narrow-band dipole antenna structure merged with the gate electrode [3].